/***************************************************************************

    jedparse.c

    Parser for .JED files into raw fusemaps.

****************************************************************************

    Copyright Aaron Giles
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:

        * Redistributions of source code must retain the above copyright
          notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above copyright
          notice, this list of conditions and the following disclaimer in
          the documentation and/or other materials provided with the
          distribution.
        * Neither the name 'MAME' nor the names of its contributors may be
          used to endorse or promote products derived from this software
          without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY AARON GILES ''AS IS'' AND ANY EXPRESS OR
    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    DISCLAIMED. IN NO EVENT SHALL AARON GILES BE LIABLE FOR ANY DIRECT,
    INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
    STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
    IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.

****************************************************************************

    Binary file format:

    Offset
        0 = Total number of fuses (32 bits)
        4 = Raw fuse data, packed 8 bits at a time, LSB to MSB

***************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "jedparse.h"



/***************************************************************************
    DEBUGGING
***************************************************************************/

#define LOG_PARSE		0



/***************************************************************************
    TYPE DEFINITIONS
***************************************************************************/

typedef struct _parse_info parse_info;
struct _parse_info
{
	UINT16		checksum;				/* checksum value */
	UINT32		explicit_numfuses;		/* explicitly specified number of fuses */
};



/***************************************************************************
    UTILITIES
***************************************************************************/

/*-------------------------------------------------
    ishex - is a character a valid hex digit?
-------------------------------------------------*/

static int ishex(char c)
{
	return (c >= '0' && c <= '9') || (c >= 'A' && c <= 'F');
}



/*-------------------------------------------------
    hexval - the hex value of a given character
-------------------------------------------------*/

static int hexval(char c)
{
	return (c >= '0' && c <= '9') ? (c - '0') : (10 + c - 'A');
}



/*-------------------------------------------------
    isdelim - is a character a JEDEC delimiter?
-------------------------------------------------*/

static int isdelim(char c)
{
	return (c == ' ' || c == 13 || c == 10);
}



/*-------------------------------------------------
    suck_number - read a decimal value from the
    character stream
-------------------------------------------------*/

static UINT32 suck_number(const UINT8 **psrc)
{
	const UINT8 *src = *psrc;
	UINT32 value = 0;

	/* skip delimiters */
	while (isdelim(*src))
		src++;

	/* loop over and accumulate digits */
	while (isdigit(*src))
	{
		value = value * 10 + *src - '0';
		src++;
	}

	/* return a pointer to the string afterwards */
	*psrc = src;
	return value;
}



/***************************************************************************
    CORE IMPLEMENTATION
***************************************************************************/

/*-------------------------------------------------
    process_field - process a single JEDEC field
-------------------------------------------------*/

static void process_field(jed_data *data, const UINT8 *cursrc, const UINT8 *srcend, parse_info *pinfo)
{
	/* switch off of the field type */
	switch (*cursrc)
	{
		case 'Q':
			cursrc++;
			switch (*cursrc)
			{
				/* number of fuses */
				case 'F':
					cursrc++;
					pinfo->explicit_numfuses = data->numfuses = suck_number(&cursrc);
					break;
			}
			break;

		/* default fuse state (0 or 1) */
		case 'F':
			cursrc++;
			if (LOG_PARSE) printf("F%c\n", *cursrc);
			if (*cursrc == '0')
				memset(data->fusemap, 0x00, sizeof(data->fusemap));
			else
				memset(data->fusemap, 0xff, sizeof(data->fusemap));
			break;

		/* fuse states */
		case 'L':
		{
			UINT32 curfuse;

			/* read the fuse number */
			cursrc++;
			curfuse = suck_number(&cursrc);
			if (LOG_PARSE) printf("L%d\n", curfuse);

			/* read digits, skipping delimiters */
			for ( ; cursrc < srcend; cursrc++)
				if (*cursrc == '0' || *cursrc == '1')
				{
					jed_set_fuse(data, curfuse, *cursrc - '0');
					if (LOG_PARSE) printf("  fuse %d = %d\n", curfuse, 0);
					if (curfuse >= data->numfuses)
						data->numfuses = curfuse + 1;
					curfuse++;
				}
			break;
		}

		/* fuse checksum */
		case 'C':
			cursrc++;
			if (cursrc < srcend + 4 && ishex(cursrc[0]) && ishex(cursrc[1]) && ishex(cursrc[2]) && ishex(cursrc[3]))
			{
				pinfo->checksum = 0;
				while (ishex(*cursrc) && cursrc < srcend)
					pinfo->checksum = (pinfo->checksum << 4) | hexval(*cursrc++);
			}
			break;
	}
}



/*-------------------------------------------------
    jed_parse - parse a .JED file that has been
    loaded raw into memory
-------------------------------------------------*/

int jed_parse(const void *data, size_t length, jed_data *result)
{
	const UINT8 *cursrc = (const UINT8 *)data;
	const UINT8 *srcend = cursrc + length;
	const UINT8 *scan;
	parse_info pinfo;
	UINT16 checksum;
	int i;

	/* initialize the output and the intermediate info struct */
	memset(result, 0, sizeof(*result));
	memset(&pinfo, 0, sizeof(pinfo));

	/* first scan for the STX character; ignore anything prior */
	while (cursrc < srcend && *cursrc != 0x02)
		cursrc++;
	if (cursrc >= srcend)
		return JEDERR_INVALID_DATA;

	/* then scan to see if we have an ETX */
	scan = cursrc;
	checksum = 0;
	while (scan < srcend && *scan != 0x03)
		checksum += *scan++ & 0x7f;
	if (scan >= srcend)
		return JEDERR_INVALID_DATA;

	/* see if there is a transmission checksum at the end */
	checksum += *scan;
	if (scan + 4 < srcend && ishex(scan[1]) && ishex(scan[2]) && ishex(scan[3]) && ishex(scan[4]))
	{
		UINT16 dessum = (hexval(scan[1]) << 12) | (hexval(scan[2]) << 8) | (hexval(scan[3]) << 4) | hexval(scan[4] << 0);
		if (dessum != 0 && dessum != checksum)
			return JEDERR_BAD_XMIT_SUM;
	}

	/* the ETX becomes the real srcend */
	srcend = scan;

	/* blast through the comment field */
	cursrc++;
	while (cursrc < srcend && *cursrc != '*')
		cursrc++;

	/* now loop over fields and decide which ones go in the file output */
	cursrc++;
	while (cursrc < srcend)
	{
		/* skip over delimiters */
		while (cursrc < srcend && isdelim(*cursrc))
			cursrc++;
		if (cursrc >= srcend)
			break;

		/* end of field is an asterisk -- find it */
		scan = cursrc;
		while (scan < srcend && *scan != '*')
			scan++;
		if (scan >= srcend)
			return JEDERR_INVALID_DATA;

		/* process the field */
		process_field(result, cursrc, scan, &pinfo);

		/* advance past it */
		cursrc = scan + 1;
	}

	/* if we got an explicit fuse count, override our computed count */
	if (pinfo.explicit_numfuses != 0)
		result->numfuses = pinfo.explicit_numfuses;

	/* clear out leftover bits */
	if (result->numfuses % 8 != 0)
		result->fusemap[result->numfuses / 8] &= (1 << (result->numfuses % 8)) - 1;
	memset(&result->fusemap[(result->numfuses + 7) / 8], 0, sizeof(result->fusemap) - (result->numfuses + 7) / 8);

	/* validate the checksum */
	checksum = 0;
	for (i = 0; i < (result->numfuses + 7) / 8; i++)
		checksum += result->fusemap[i];
	if (pinfo.checksum != 0 && checksum != pinfo.checksum)
		return JEDERR_BAD_FUSE_SUM;

	return JEDERR_NONE;
}



/*-------------------------------------------------
    jed_output - generate a new .JED file based
    on the jed_data provided
-------------------------------------------------*/

size_t jed_output(const jed_data *data, void *result, size_t length)
{
	UINT8 *curdst = (UINT8 *)result;
	UINT8 *dstend = curdst + length;
	int i, zeros, ones;
	char tempbuf[256];
	UINT16 checksum;
	UINT8 defbyte;
	UINT8 *temp;

	/* always start the DST with a standard header and an STX */
	tempbuf[0] = 0x02;
	sprintf(&tempbuf[1], "JEDEC file generated by jedutil*\n");
	if (curdst + strlen(tempbuf) <= dstend)
		memcpy(curdst, tempbuf, strlen(tempbuf));
	curdst += strlen(tempbuf);

	/* append the package information */
	sprintf(tempbuf, "QF%d*\n", data->numfuses);
	if (curdst + strlen(tempbuf) <= dstend)
		memcpy(curdst, tempbuf, strlen(tempbuf));
	curdst += strlen(tempbuf);

	/* compute the checksum */
	checksum = 0;
	for (i = 0; i < data->numfuses / 8; i++)
		checksum += data->fusemap[i];
	if (data->numfuses % 8 != 0)
		checksum += data->fusemap[data->numfuses / 8] & ((1 << (data->numfuses % 8)) - 1);

	/* determine if we are mostly 0's or mostly 1's */
	for (i = zeros = ones = 0; i < data->numfuses / 8; i++)
		if (data->fusemap[i] == 0x00)
			zeros++;
		else if (data->fusemap[i] == 0xff)
			ones++;
	defbyte = (ones > zeros) ? 0xff : 0x00;

	/* output the default fuse state */
	sprintf(tempbuf, "F%d*\n", defbyte & 1);
	if (curdst + strlen(tempbuf) <= dstend)
		memcpy(curdst, tempbuf, strlen(tempbuf));
	curdst += strlen(tempbuf);

	/* now loop over groups of 32 fuses and output non-default groups */
	for (i = 0; i < data->numfuses; i += 32)
		if (data->fusemap[i / 8 + 0] != defbyte ||
			data->fusemap[i / 8 + 1] != defbyte ||
			data->fusemap[i / 8 + 2] != defbyte ||
			data->fusemap[i / 8 + 3] != defbyte)
		{
			int stroffs;
			int j;

			/* build up a string of 32 fuses */
			stroffs = sprintf(tempbuf, "L%05d ", i);
			for (j = 0; j < 32 && i+j < data->numfuses; j++)
				tempbuf[stroffs++] = '0' + jed_get_fuse(data, i + j);
			stroffs += sprintf(&tempbuf[stroffs], "*\n");

			/* append to the buffer */
			if (curdst + strlen(tempbuf) <= dstend)
				memcpy(curdst, tempbuf, strlen(tempbuf));
			curdst += strlen(tempbuf);
		}

	/* write the checksum */
	sprintf(tempbuf, "C%04X*\n", checksum);
	if (curdst + strlen(tempbuf) <= dstend)
		memcpy(curdst, tempbuf, strlen(tempbuf));
	curdst += strlen(tempbuf);

	/* now compute the transmission checksum */
	checksum = 0;
	for (temp = (UINT8 *)result; temp < curdst && temp < dstend; temp++)
		checksum += *temp & 0x7f;
	checksum += 0x03;

	/* append the ETX and the transmission checksum */
	tempbuf[0] = 0x03;
	sprintf(&tempbuf[1], "%04X", checksum);
	if (curdst + strlen(tempbuf) <= dstend)
		memcpy(curdst, tempbuf, strlen(tempbuf));
	curdst += strlen(tempbuf);

	/* return the final size */
	return curdst - (UINT8 *)result;
}



/*-------------------------------------------------
    jedbin_parse - parse a binary JED file that
    has been loaded raw into memory
-------------------------------------------------*/

int jedbin_parse(const void *data, size_t length, jed_data *result)
{
	const UINT8 *cursrc = (const UINT8 *)data;

	/* initialize the output */
	memset(result, 0, sizeof(*result));

	/* need at least 4 bytes */
	if (length < 4)
		return JEDERR_INVALID_DATA;

	/* first unpack the number of fuses */
	result->numfuses = (cursrc[0] << 24) | (cursrc[1] << 16) | (cursrc[2] << 8) | cursrc[3];
	cursrc += 4;
	if (result->numfuses == 0 || result->numfuses > JED_MAX_FUSES)
		return JEDERR_INVALID_DATA;

	/* now make sure we have enough data in the source */
	if (length < 4 + (result->numfuses + 7) / 8)
		return JEDERR_INVALID_DATA;

	/* copy in the data */
	memcpy(result->fusemap, cursrc, (result->numfuses + 7) / 8);
	return JEDERR_NONE;
}



/*-------------------------------------------------
    jedbin_output - generate a new binary JED file
    based on the jed_data provided
-------------------------------------------------*/

size_t jedbin_output(const jed_data *data, void *result, size_t length)
{
	UINT8 *curdst = (UINT8 *)result;

	/* ensure we have enough room */
	if (length >= 4 + (data->numfuses + 7) / 8)
	{
		/* store the number of fuses */
		*curdst++ = data->numfuses >> 24;
		*curdst++ = data->numfuses >> 16;
		*curdst++ = data->numfuses >> 8;
		*curdst++ = data->numfuses >> 0;

		/* copy in the rest of the data */
		memcpy(curdst, data->fusemap, (data->numfuses + 7) / 8);
	}

	/* return the final size */
	return 4 + (data->numfuses + 7) / 8;
}

